Apparatus for drawing glass.



I H. G. SLINGLUFF. APPARATUS FOR DRAW1NG GLASS. 1 APPLICATION FILEDNOV. 1. m2. RENEWED APR. 1,1916. 1,203,423.

Patnted Oct. 31, 1916.

I ATTDORNEYT UNITED srA'rEs PATENT orrron.

HARRY G. SLINGLUFF, OF MOUNT VERNON, OHIO, ASSIGNOR T PITTSBURGH PLATEGLASS COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OFIEENN'S'YIII- VAN IA.

APZPARATUS FOR DRAWING GLASS.

Patented Oct. 31, 1916.

Application filed November 1, 1912, Serial No. 729,080. Renewed April 7,1916. Serial No. 89,725.

To all whom it may concern:

Be it known that I, HARRY G. SLINGLUFF,

.a citizen of the United States, residing at granted to me for the newand useful Improvements in Apparatus for Drawing Glass, of which thefollowing is a specification.

This invention has reference to the provision of an improved apparatussuch as is' used in connection with the drawing of glass cylinders inthe manufacture of window glass. The first of the objects of my presentinvention is the construction of apparatus of the character specified inwhich the bad efi'ects of uneven temperature ondifierent sides of thecylinder are automatically obviated. In the-drawing of-cylinders fromsocalled deep furnace extensions which project at one end of 'the mainfurnace, it is found that the heat of the main furnace will interferewith the uniformity of production on opposite sides of the cylinderbecause that side of the cylinder being drawn which is nearest the bodyof the furnace will generally be exposed to a greater degree of heatthan the side of the cylinder which is more remote. In the practice ofmy invention, I provide means for compensating for such unequal heatingeifect and thus obtain a cylinder which will be of substantially uniformthickness all around and avoid the formation of other defects in theglass such as ropy structure or a structure not of the highest grade.

In order that my invention may be better understood, I have illustratedit in preferred form in the accompanying drawings wherein- Figure l is aplan view of a deep furnace extension with 'my improvement appliedthereto, and Fig. 2 is a sectional view taken on the line II-II ofFigure 1.

I have not shown in these drawings the apparatus employed forraising thebait or shown a portion of the main chamber of the furnace marked 3containing a body of molten glass, 4, which extends out into a furnaceektension, 5, having in the upper part an aperture in which is placed atop-stone,

6, constructed to be raised and lowered so and it is of course providedwith suitable means for raising and lowering it and with a cap or coverto close the opening 7 when the stone is raised and the drawing is nottaking place. The blow-pipe or bait which I have indicated at 8 may beof any known form and is provided with a tubular handle or stem 9through which air under pressure is admitted in the usual way, and withsuitable raising and lowering mechanism.

In a position partially immersed in the body.of glass, t, and underneaththe topstone, 6, I place what may be called a drawstone, 10. Thisdraw-stone is preferably square as shown, to prevent it rotating byengagement with the projecting parts 11, and is also preferably wedgedin suitable position within the glass by means of the wedges 11. Thisconstruction permits of vertical adjustment of the draw-stone. IVithinthe draw-stone 10 which somewhat resembles a ring in shape, there is achamber which has on the side away from the.

- clearly shown in Figure 2. At the opposite for supplying said baitwith air which is side of the chamber within the draw-stone, 10, thatis, the side which is nearest the body 3 of the furnace, I provide asloping wall, 13, which extends a considerable distance beneath thesurface of the glass, and is preferably gradually decreased in theamount of its incline until it merges with the vertical wall, 12, on theopposite side, thus producing in general the effect of an offset tubularaperture in the draw-stone indicated in Figure 1.

The operation of my invention is substantially as follows. A cylinder,indicated at 14, being started upward by means of the bait 8 andblow-pipe 9; from the surface of the glass within the draw-stone 10, the

effect of the heat on opposite sides of the p draw-stone, which is at alower temperature near the wall 12 than it is near the wall 13 will tendsuch an equilibrium of forces is encountered as will hold fixed positionwith regard to the drawstone, which normally I have found will be atsome place or zone where the wall of the cylinder at the right asindicated at 15 Will be in position over the inclined surface 13 whichis under the surface of the glass. The square shape of the draw-stone 10serves to keep the inclined surface 13 on the side nearest the body ofthe furnace, and the combination of the said inclined surface 13 in thatposition and the substantially upright surface 12 on the opposite sideof the draw-stone, I have found in practice automatically serves to holdthe cylinder in its proper position and also avoids the ropy andimperfect effects otherwise produced by other forms of apparatus. hedraw-stone 10 is to be made of any suitable material, .but I prefer theuse of certain kinds of refractory clay ordinarily employed in thisclass of construction.

aving thus described my invention and illustrated its use, what I claimas new and desire to secure by Letters Patent is the following:

1. In combination in apparatus for drawing glass cylinders, a drawingtank containing a body of glass and heated to a greater extent on oneside than on the other, draw stone lying in the tank surrounded by theglass thereof,

substantially vertical.

.2. In combination in apparatus for drawthat such remaining itrelatively in substantially side of the vertical plane of the remainingportion of the periphery of the cylinder so portion is unshielded fromthe body of glass beneath the draw stone.

3. In combination in apparatus for drawing glass cylinders, a drawingtank oontaining a body of glass and heated to a greater extenton oneside than on the other, and a draw stone lying in the tank surrounded byb an opening therethrough with the wall thereof toward the more highlyheated side of the tank extended laterally beneath a portion ofthe edgeof the cylinder being drawn and having the opposite wall of the openinglying to one side of the vertical plane of the remaining portion of theperiphery of the cylinder so that such remaining portion is unshieldedfrom the body of glass beneath the draw stone.

4. In combination in apparatus for draw ing glass cylinders from a bodyof glass heated to a greater extent on one side than on the other, adraw stone lying partially immersed in the bodyof glass and havingsurface of the glass.

5. In combination in apparatus for drawing glass cylinders from a bodyof glass heated to a greater extent on one side than on the other, adraw stone lying partially surface of the glass being nearer to the sideof the body of glass most highly heated than the center of the otherarea. In testimony whereof I have hereunto signed my name in thepresence of the two subscribed Witnesses.

HARRY G. vSLINGrLUFF. Witnesses:

H. .1 IIITRER, BANNER M. ALLEN.

